1. Field of the Invention
The present invention relates to methods and devices for applying a sealant to components which is used when a package of an electronic component is bonded.
2. Description of the Related Art
The package of an electronic component requires air-tight sealing to prevent the entry of moisture, flux, and the like, which may impair the function of an internal element. Thus, in general, a sealant such as an adhesive or solder is evenly applied to a sealing part of a package. After that, air-tightness is achieved by hardening or heat-fusion sealing.
As a method for applying a sealant to the package of an electronic component, a method for directly transferring the sealant to a sealing surface is mainly used. As shown in FIGS. 1A to 1C, this is a method in which a liquid sealant 2 of a film of a specified thickness is formed on an application base 1, and a sealing surface 3a of a component (a cap in this case) 3 is pressed on the sealant 2 to apply the sealant 2 to the entirety of the sealing surface 3a. The direct transferring method has advantages such as being achieved by a simple device, being capable of easily applying the sealant to the entire sealing surface 3a and being capable of simultaneously applying the sealant to a plurality of components 3, which leads to high productive efficiency.
However, in the case of the direct transferring method, the sealant is prone to extend onto the side surfaces of the component 3, as shown in FIG. 1C, by which there is a problem in that only a small amount of sealant 2 can adhere on the surface 3a used for sealing. In addition, the amount of the sealant applied tends to be uneven. As a result, sealing failure due to a local insufficiency of the sealant 2, contamination of a tool due to the sealant 2 adhered on the side surfaces, and dimensional inaccuracy tend to occur.
The present invention cam solve the problem associated with the conventional art and provide a method for applying a sealant to a component, in which the sealant can be evenly applied to a sealing surface of the component without extending onto the other surfaces, and a device therefor.
The method for applying a sealant to a component in which the sealant is applied to a part or the entirety of a sealing surface of the component includes the step of disposing an abutting member approximately in parallel to a surface of the sealant in a sealant liquid formed into a film of a specified thickness, the step of pressing the sealing surface of the component, to the abutting member disposed in the sealant formed into a film, and the step of transferring the sealant to the sealing surface of the component by pulling the component apart from the sealant.
The device for applying a sealant to a sealing surface of a component has an application base, a liquid sealant film of a specified thickness disposed on the application base, and an abutting member disposed approximately in parallel to a surface of the sealant in the sealant. The sealant is transferred onto the sealing surface of the component by pulling the sealing surface apart from the abutting member after pressing the sealing surface thereto.
The abutting member is disposed on the application base, and a film of the sealant having a specified thickness is formed in such a manner that the surface of the sealant is approximately in parallel to the surface of the abutting member. Next, the sealing surface of the component is pressed to the abutting member, and at the same time, is contacted with the sealant. With this arrangement, sinking of the sealing surface can be prevented. As a result, the sealant existing on the top surface of the abutting member or a gap between a plurality of abutting members adheres to the sealing surface of the component. Next, when the component is pulled apart from the sealant, the sealant adhered on the sealing surface is also pulled apart with the component, and the sealant is thereby transferred.
Regarding the sealant transferred in the way described above, since sinking of the component can be prevented by the abutting member, only a small amount of the sealant extends onto the side surfaces of the component, in contrast with a conventional method, and a large amount of the sealant can adhere on the sealing surface. Furthermore, since the amount of the sealant adhered on the sealing surface is even, the problem of sealing failure can be solved.
As the above abutting member, it is preferable to use a meshed member. In other words, in the case of the meshed member, since it has a planar form in which a series of meshed holes are regularly aligned, evenness of the amount of the sealant adhered on the sealing surface can be achieved.
In addition, the abutting member may be a plurality of small bumps protruding upwardly distributed on the application base. In this case, similarly, sinking of the component can be prevented by the top surfaces of the small bumps, and a large amount of the sealant can be applied to the sealing surface by filling the sealant in a gap between the small bumps.
Furthermore, the abutting member is not restricted to a meshed member or a small bump. Any type of member, for example, a porous plate, can be used as long as the member has a structure that prevents the component from sinking and inhibits the sealant from adhering onto the sealing surface of the component.
Preferably, the sealant application method according to the present invention is used in a case in which an adhesive such as an epoxy adhesive is applied to the sealing surface of a component, since the adhesive can be evenly applied to the sealing surface.
In addition, the method of the present invention can be used not only for the method in which a film of a sealant is formed on an application base and a component is pressed from above, but for a method in which a sealant is filled in a thick meshed member or a porous plate to dispose the meshed member or the porous plate flush against the component so as to transfer the sealant.
For the purpose of illustrating the invention, there is shown in the drawings several forms which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.